iface-modem: Increase unlock_required retries

If a SIM is known to exist, for e.g. if it was created during load_sim_slots,
persist a few more times before giving up on the SIM to be ready. There
are modems on which the SIM takes more than 15s to be ready, luckily,
they happen to be QMI modems where the SIM's iccid in load_sim_slots
lets us know that there is a sim.

src/mm-iface-modem.c

@@ -346,8 +346,6 @@ mm_iface_modem_abort_invocation_if_state_not_reached (MMIfaceModem          *sel
 /*****************************************************************************/
 /* Helper method to load unlock required, considering retries */
 
-#define MAX_RETRIES 6
-
 typedef struct {
     guint retries;
     guint pin_check_timeout_id;
@@ -383,6 +381,28 @@ load_unlock_required_again (GTask *task)
     return G_SOURCE_REMOVE;
 }
 
+#define MAX_RETRIES_NO_SIM 6
+#define MAX_RETRIES_SIM_EXISTS 30
+static guint
+get_max_retries (MMIfaceModem *self)
+{
+    g_autoptr(MMBaseSim) sim = NULL;
+
+    g_object_get (self,
+                  MM_IFACE_MODEM_SIM,
+                  &sim,
+                  NULL);
+    /* If a SIM is known to exist, for e.g. if it was created during load_sim_slots,
+      persist a few more times before giving up on the SIM to be ready. There
+      are modems on which the SIM takes more than 15s to be ready, luckily,
+      they happen to be QMI modems where the SIM's iccid in load_sim_slots
+      lets us know that there is a sim. */
+    if (sim)
+        return MAX_RETRIES_SIM_EXISTS;
+
+    return MAX_RETRIES_NO_SIM;
+}
+
 static void
 load_unlock_required_ready (MMIfaceModem *self,
                             GAsyncResult *res,
@@ -418,7 +438,7 @@ load_unlock_required_ready (MMIfaceModem *self,
         }
 
         /* For the remaining ones, retry if possible */
-        if (ctx->retries < MAX_RETRIES) {
+        if (ctx->retries < get_max_retries (self)) {
             ctx->retries++;
             mm_obj_dbg (self, "retrying (%u) unlock required check", ctx->retries);
 
@@ -436,7 +456,7 @@ load_unlock_required_ready (MMIfaceModem *self,
                                  MM_MOBILE_EQUIPMENT_ERROR,
                                  MM_MOBILE_EQUIPMENT_ERROR_SIM_FAILURE,
                                  "Couldn't get SIM lock status after %u retries",
-                                 MAX_RETRIES);
+                                 get_max_retries (self));
         g_object_unref (task);
         return;
     }
@@ -458,7 +478,7 @@ internal_load_unlock_required_context_step (GTask *task)
     g_assert (ctx->pin_check_timeout_id == 0);
     MM_IFACE_MODEM_GET_INTERFACE (self)->load_unlock_required (
         self,
-        (ctx->retries == MAX_RETRIES), /* last_attempt? */
+        (ctx->retries >= get_max_retries (self)), /* last_attempt? */
         (GAsyncReadyCallback) load_unlock_required_ready,
         task);
 }